Jet Boat Finally got it Right.

1991 Alumaweld Jet Boat

After a long battle with the Evinrude 150 HP jet outboard, we finally have it right. After replacing all of the ignition components last year, we let the boat sit until March. As stripper season was approaching, I suggested that we take the boat out and see if it would perform. Blair and I took the boat up to Lake Oroville and launched. We had limited time and gas, so we made a couple of runs outside the buoy line. We both felt the boat was finally running on all cylinders and performing as it used to. We loaded the boat back up and celebrated our victory.

Not so Fast! Blair took the boat out for the first stripper fishing trip of the season and reported that the motor was not coming up to high RPM, and was sluggish getting out of the water. Very differently than it behaved at Lake Oroville. What the heck happened. We had not touched anything since our trip to Oroville. How could it be wrong again???

I ordered up another new/old stock timer base and started all over again. I took the boat outside and hooked it up to a water hose and started it up. I removed the spark plug wires one at a time and found cylinder number 6 was not firing. I switched around the leads going to the spart coils and found that the power pack was not sending the pulse to # 6. it is possible to change the power pack without pulling the flywheel. I replaced the power pack with one that I had used previously. It did not fix the problem. Cylinder #6 was still not firing. Okay, it must be the timer base. I pulled the flywheel off and replaced the timer base with the new/old stock unit I had purchased from Ebay. Number 6 was still dead. How could that be? I pulled the flywheel again and put the last timer base back on and tried again. Number 6 was now firing. It was firing with the combination of ignition components that was not working before. What had happened? I finally concluded that each one of the ignition components that I purchased from Ebay were used or new/old stock. Each one of them came with it's own rubber connector. I believe that all of the components were likely functional, and that the couplers were just dirty or corroded. The mere act of replacing the ignition components was manipulating the couplers and effecting the performance of the components. I cleaned up the couplers with alcohol and re-tested and all the cylinders were firing.

At some point, I finally used Occom's Razor in my thinking. The simplest solution is usually the right one. I was stuck in my thinking that all of the components I was buying were bad. In fact, the wire couplings were to blame. The couplers had been sitting on somebody's shelf for 30 years and should have been inspected and cleaned before installation. That is a much simpler answer than all of the components were bad.

Blair has now been fishing with the boat for several trips. The engine is running flawlessly and producing all the power it should.

The lesson here is simple. The simpler solution is likely the right one.